staging: wfx: data_tx.h: remove space after cast

remove extra space after a cast in file data_tx.h

Signed-off-by: Kaaira Gupta <kgupta@es.iitr.ac.in>
Link: https://lore.kernel.org/r/20200310142509.25632-5-kgupta@es.iitr.ac.in


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>